The incidence of enteric disease on the Navajo and Hopi Indian reservations is greater than that of adjacent non-reservation areas. This may be due in part to the use of wastewater treatment facilities which may not adequately remove human enteric pathogens. The purpose by isolates of efficient wastewater treatment facilities. Organisms which actively produce antimicrobial agents of suitable activity spectrum could be used to improve the removal of human pathogens from inefficient wastewater treatment systems. The specific aims of the project are: to isolate and purify algae and bacteria which produce antimicrobial substances, to determine the activity spectrum of the agents, to purify the agents, to determine abiotic factors which control the production of the antimicrobial compounds, and to carry out a limited chemical and physical characterization of the agents. In addition to the research aims, this project will stress research training for the student participants involved. Minority biomedical students will be trained extensively in the microbiological skills, especially those pertaining to the handling of human pathogens. The students will collect samples from treatment systems and isolate microorganisms. They will also be trained in the operation of analytical equipment such as spectrophotometers (IR and UV), gas chromatographs and electrophoresis equipment. The students will also design experiments, collect and analyze results and be actively involved in the dissemination of the research conclusions by presentations at scientific meetings.